Several governments assert their negotiators are on track to begin drafting a comprehensive accord next month.

Iranian Foreign Minister Mohammad Javad Zarif and Catherine Ashton, European Union high representative, dined on Monday night before the opening plenary sessions, as they have on the eve of every session since negotiations began in earnest last year.

In Moscow, Russian officials set moderate expectations for the latest round of talks, conducted at the political directors’ level between the governments of Iran and the P5+1 powers – the United States, United Kingdom, France, China, Russia and Germany.

Deputy Foreign Minister Sergei Ryabkov said that Moscow had “no special expectations” for the talks, which should be oriented towards building a framework for the continuation of talks, he told a local news media.

And yet Iranian officials hope to “get to the details” quickly and “start writing the text” of a comprehensive agreement that would end the impasse.

“We hope that in the upcoming talks, we would be able to bring the views closer and narrow the differences regarding major issues,” Iran’s Deputy Foreign Minister Abbas Araqchi told Press TV, a state-run Iranian news agency.

The aim of the talks is to hammer out a long-term deal to define the permissible scope of Iran’s nuclear program in return for a lifting of sanctions that are damaging its oil-dependent economy.

Ahead of the resumption of talks, a senior Obama administration official told journalists that any final deal would be “highly, highly technical,” and that the negotiation sessions through April would be focused on working through each detail, piece by piece.

The parties “set out a work plan of how we were going to proceed to get to a comprehensive agreement, and we are on pace with the work plan that was set out,” the official said, adding that the drafting of the deal might begin in May.

The upbeat tone from Tehran came amid US concerns that Russia and Iran mightsoon sign an oil-for-good agreement valued at $20 billion.

“We’ve been very clear about our concerns with both parties regarding this or any similar deal,” the senior official said in response to reports. “If such a deal were to happen, it appears it would be inconsistent with the terms of the P5+1 plus European Union Joint Plan of Action, and could potentially trigger US sanctions against the entity and individuals involved in any related transaction.”

In a conversation with The Jerusalem Post, an Obama administration official delineated between actions inconsistent with the Joint Plan of Action – the interim nuclear deal forged in Geneva last fall granting the parties six months to negotiate a final agreement.

Proportionate sanctions would be triggered should such “inconsistent” action be taken, the official said.

However, the US has assessed that “Iran has abided by the JPA,” State Department spokeswoman Jen Psaki said on Monday.

Responding to the reports, Senate Foreign Relations Committee chairman Robert Menendez (D-New Jersey) and Senator Mark Kirk (R-Illinios) wrote to US President Barack Obama on Monday, calling on the president to put Iran “on notice” for skirting the interim deal.

“If Iran moves forward with this effort to evade US sanctions and violate the terms of oil sanctions relief provided for in the JPA, the United States should respond by reinstating the crude oil sanctions, rigorously enforcing significant reductions in global purchases of Iranian crude oil and sanctioning any violations to the fullest extent of the law,” the two senators wrote.